1. Technical Field
This invention generally relates to light reflectors, and more specifically relates to a light reflector that images a high-intensity light beam at a distant location.
2. Background Art
Light reflectors have long been used to bounce light off of a reflective surface. Light generally shines in all directions from a light source. However, if light shining in all directions from a light source is not useful, a reflective surface can be employed to reflect light from a direction in which it is not useful and projected towards a direction in which the light is useful. In this way, light reflectors increase the amount of light shining in a desired direction.
Various conventional devices relate to light reflectors. Examples of patents pertinent to the present invention include:
U.S. Pat. No. 5,695,277 to Kim for a light source apparatus for generating parallel light having dual mirrors for eliminating lamp shadow effects; PA1 U.S. Pat. No. 5,636,917 to Furami et al. for a projector type head light; PA1 U.S. Pat. No. 5,544,029 to Cunningham for a lighting fixture for theater, television and architectural applications; PA1 U.S. Pat. No. 5,446,637 to Cunningham et al. for a lighting fixture; PA1 U.S. Pat. No. 5,345,371 to Cunningham et al. for a lighting fixture; PA1 U.S. Pat. No. 5,268,613 to Cunningham for an incandescent illumination system; PA1 U.S. Pat. No. 5,235,499 to Bertenshaw for a lamp system having a toroidal light emitting member; PA1 U.S. Pat. No. 5,143,447 to Bertenshaw for a lamp system having a toroidal light emitting member; PA1 U.S. Pat. No. 4,956,759 to Goldenberg et al. for an illumination system for non-imaging reflective collector; PA1 U.S. Pat. No. 4,947,305 to Gunter, Jr. for a lamp reflector; PA1 U.S. Pat. No. 4,899,261 to Blusseau et al. for an automobile headlamp with small height and high flux recovery; PA1 U.S. Pat. No. 4,800,467 to Lindae et al. for a dimmed headlight, particularly for motor vehicles; PA1 U.S. Pat. No. 4,241,382 to Daniel for a fiber optics illuminator; PA1 U.S. Pat. No. 4,041,344 to LaGiusa for an ellipsoidal reflector lamp; PA1 U.S. Pat. No. 3,770,338 to Helmuth for a fiber optics light source; PA1 U.S. Pat. No. 1,711,478 to Halvorson, Jr. for a light reflector; and PA1 U.S. Pat. No. 254,578 to Wheeler for a reflector;
each of which is herein incorporated by reference for its pertinent and supportive teachings.
Problems exist among the aforementioned patent references. Typically, despite the use of reflectors, an excessive amount of light emitted by a light source is not projected in the desired direction. Instead, light becomes misdirected and absorbed by the non-reflective components in a light fixture. The misdirected light wastes electrical energy and leads to the undesired heating of the light fixture components. In many instances, the components of a light fixture become warped by the excessive heat, and therefore must be replaced.
Problems due to excessive heat have partially been solved by incorporating a fan into the light fixtures. Typically, a fan draws air across a surface of the hot light fixture components. The use of fans is only a partial solution, however, for reflector lights which operate in environments polluted with dust, pollen, oils, and other particulate and vaporous matter. In that case, the polluted air enters into and deposits onto light fixture equipment. Cleaning of these deposits must occur regularly to prevent damage to sensitive equipment parts as well as to maintain peak performance of the equipment. Such cleaning problems are expensive to remedy, requiring many hours of labor to correct. During cleaning, the equipment is inoperable which results in a loss in productivity.
Another problem exists when the reflective components of a light fixture include lenses, which are used to shape the projected light beam. Lenses themselves contribute to misdirected and absorbed light. Additionally, lenses make up a significant portion of the weight and cost of a light fixture, and are subject to breakage.
Still another problem is that the projected light can sometimes have an intensity varying radially such that a concentric light pattern is projected. The undesired concentric ring pattern occurs because of variations in the shape of the bulb. In addition, the filament in the lamp appears as an image. Attempts to eliminate the filament shadow and concentric ring pattern have resulted in an increased amount of misdirected light.
A further problem is that light fixtures with reflective components typically emit an undesired amount of infrared light along with the desired visible light. This infrared light unduly heats the area on which the projected light is imaged, which is undesirable for light fixtures used in theater, television, and architectural applications. The reflection of undesired infrared light leads to further heating of the light fixture components.
Thus, there is a need to provide a light reflector which reduces misdirected and absorbed light. There is also a need to provide a light reflector which can shape a projected light beam without requiring the use of lenses. Further, there is a need to provide a light reflector which can minimize the concentric ring pattern. And, there is a need to provide a light reflector which does not unduly transmit infrared light. Finally, there is a need to protect light fixture equipment from heat damage as well as the pollution deposits caused by circulating polluted air through the equipment as a means to dissipate heat. These, and other identified needs, are satisfied by the present invention.